Method of killing microprobes with microbicidal compounds and ultraviolet light

ABSTRACT

Microbicidal effects are provided by stimulating the activity of certain compositions by exposing them to light energy in the visible or ultraviolet range of the electromagnetic spectrum.

United States Patent Charles S. Castner 213 Revere Blvd., Lincoln Park,Reading, Pa. 19609 Apr. 12, 1967 Jan. 26, 1971 lnventor Appl. No. FiledPatented METHOD OF KILLING MICROPROBES WITH MICROBICIDAL COMPOUNDS ANDULTRAVIOLET LIGHT 5 Claims, No Drawings US. Cl 128/172.1 Int. Cl A6lm31/00 Field of Search 250/43, 84;

Primary Examiner-James W. Lawrence Assistant Examiner-A. L. BirchAttorney-Buell, Blenko & Ziesenheim ABSTRACT: Microbicidal effects areprovided by stimulating the activity of certain compositions by exposingthem to light energy in the visible or ultraviolet range of theelectromagnetic spectrum.

METHOD OF KILLING MICROPROBES WITH MICROBICIDAL COMPOUNDS ANDULTRAVIOLET LIGHT This invention relates to methods and means forkilling microbes and, more particularly, relates to a system thatincludes certain reactive materials whose microbicidal effects may bestimulated by exposing these materials to energy in the form of visibleor ultraviolet light.

At the outset, it may be convenient to define several terms that areused in this specification and in the accompanying claims. The termmicrobe (and any terms derived therefrom) is used in its conventionalsense to refer to any small organisms, including both pathogenic andnonpathogenic organisms. The terms antimicrobial compositions" and andmicrobicides" are used to indicate not only those compositions that areinherently microbicidal, but also those compositions that may becomemicrobicidal in certain environments or under certain conditions of use.Such terms as kill and killing" are used to describe not only the actualkilling of microbes, but also the inhibition of microbial generation andregeneration and other morbid processes.

Most common germicides suffer from the defect that when used ineffective quantities and concentrations, they may cause certaindesirable side etfects. Not only is this true of the comparativelyrecently discovered antibiotics, but it also applies to the standardgennicides such as iodine and mercurochrome. For example, as is wellknown, iodine, when ap plied in a dilute solution, is an acceptableantiseptic. However, as the tincture evaporates, a stronger and strongersolution results until such time as only iodine and iodine compoundsremain. If the surface to which the iodine has been applied is a wound,the residual iodine, after the tincture has evaporated, will burn thehealthy tissue, delay healing of the wound, and sometimes cause scartissue to be formed.

From the foregoing, it can be seen that an ideal microbicide for use intreating human beings and other animal life should be effective to killmicrobes but, at the same time, should be nontoxic and noncaustic toanimal tissue and should leave no lingering side effects.

Accordingly, it is an object of this invention to prepare compositionsand provide methods and apparatus for their use that will providemicrobicidal effects. I

Another object of this invention is vto provide microbicidalcompositions and methods and apparatus for their use that aresubstantially nontoxic to animal life and will have no lingering sideeffects or toxicity after their microbe-killing function has beencompleted.

Still a further object of this invention is to provide methods andapparatus whereby substantially nontoxic materials can be controllablystimulated to increase their germicidal activity.

Briefly, the objects of this invention are achieved by utilizing certaincompositions that, under the incidence of various light sources, becomestimulated to increase their microbicidal effects. Due to the factthat'the light source may be turned off and on at will, substantially notoxicity or damage to living tissue will result except under thepreselected conditions of use.

The compositions of this invention may be used in comparatively diluteform so that they. will be nontoxic to animal life. These materials maybe flushed into a wound or other diseased area of the body and be givena period of time to out and penetrate the area of desired treatment.Sufficient time can be given to allow these materials to impregnatesince, in their dilute form, they are substantially nontoxic andnoncaustic.

After the desired impregnation has been achieved, the compositions ofthis invention are stimulated to increase their microbicidal activity tosuch a degree that they will rapidly kill pathogenic organisms. After asufficient length of treatment, the light source may be removed and theremaining materials that have not been consumed during treatment willreturn to their relatively passive state and once again becomesubstantially nontoxic and noncaustic. Thus, it can be seen that bytreatment in accordance with this invention, there will be no toxicresiduum for systemic absorption.

By way of example, as suitable materials for use in this invention,there may be mentioned certain photopolymerization reagents that, underthe influence of an ultraviolet lamp, will cause the polymerization ofcertain materials such as the vinyls and acrylics. It is believed thatthese materials, under the influence of ultraviolet light, become strongoxidizing or oxygenation agents. When the light source is discontinued,the material that has not been consumed reverts to its previous passivelevel that is nontoxic and noncaustic to animal life. By way of example,the following photopolymerization reagents may be mentioned: acridineorange, azo-bis-iso-butyronitrile, benzil, benzoin, benzoyl peroxide,diacetyl, 4,5-dibromo fluorescein-Na, ethyl red, flazo orange,flourescein amine, flourescien isothiocyanate, lauroyl peroxide,methylene blue, and rose bengal.

The particular advantage of using the above-enumeratedphotopolymerization reagents lies in the fact that their activity may bestimulated by energy in the near ultraviolet range of theelectromagnetic spectrum, that is, from approximately 3,200 to about4,000 Angstrom units, and preferably with a strong peak in the range of3,500 to 3,700 Angstrom units. As is known, ultraviolet light by itselfmay be highly microbicidal, however, the effective microbicidal range isfrom about about 2,500 to 2,800 Angstrom units. Unfortunately, energy inthis frequency range not only is microbicidal, but may burn andotherwise damage healthy tissue. For this reason, ultraviolet light forthe treatment of animal tissue has been severely limited since theundesirable side effects and burns may be worse than the benefit gained.However, this problem is greatly alleviated in the practice of theinstant invention due to the fact that ultraviolet light of microbicidalintensity is not required rather, there is required only a lowerintensity of ultraviolet light as is necessary to stimulate thecompositions of this invention.

The above discussion has particular pertinency with respect to thetreatment of open wounds, incisions, and the like. Here it can beappreciated that to treat the exposed flesh with ultraviolet light only,it is necessary for the intensity of the ultraviolet light to besufficiently great to penetrate through the surrounding blood and othermaterial to reach and penetrate the infected tissue. When materials areused in accordance with this invention, however, it is necessary only topermit these materials to impregnate the infected tissue to the desireddegree and then use a comparatively weaker source of ultraviolet energythat need be only sufficiently intense to stimulate the materials ratherthan sufficiently intense to be effective as a microbicidal agent perse.

As was noted above, the photopolymen'zation reagents listed above are ofparticular interest since theiractivity may be stimulated atconsiderably longer frequencies than those that are so damaging toanimal tissue. Since these materials will respond effectively atfrequencies as high as about 3,700 Angstrom units, they will havelittle, if any, effect upon healthy animal tissue if coiitrollably used.

ln the practice of this invention, certain beneficial side effects canbe obtained. For example, the compositions of this invention may bemixed with conventional biostains that, under the influence ofultraviolet light, are capable of distinguishing healthy tissue fromdiseased or dead tissue. Thus, as would be the case in an open wound,the person delivering treatment is given a visual presentation of thelocation of greatest damage and the focus where greatest care andthoroughness of treatment are required.

Also, due to the fluorescent nature of the biostains such as thefluorescein compounds, the treatment of tissue in accordance with thisinvention will provide visual representation of the exact area that hasbeen treated, thus preventing, to a large degree,the accidental omissionof treatment of the infected area.

This invention provides means for giving immediate first aid to preventinfections from developing in woundsand injuries. In one aspect of thisinvention, it is contemplated that a small portable source ofultraviolet energy will be provided that can be hand held and directedinto a wound impregnated with with the compositions of this invention.Such a portable unit would be particularly desirable for emergencytreatment in ambulances and emergency wards as well as for emergencytreatment on the battle field for wounded troops.

in one preferred modification of this invention, the portable source ofultraviolet energy is provided with a small diameter rod of quartz orother ultraviolet light transmitting material so that a fairly smallarea of light can be directed into the infected area. Advantageously,the energy source may contain both near ultraviolet and far ultravioletlight as well as a directed curtain of visible light. The nearultraviolet light will stimulate the activity of the microbicidalcompounds, the far ultraviolet light will provide penetration into theinfected area, and the visible light will act as a shield to preventintrusion of extraneous incidental light.

Although certain embodiments of the invention have been described in thespecification, it is to be understood thatthe invention is not limitedthereto, is capable of modification, and can be rearranged withoutdeparting from the spirit and scope of the invention.

1 claim:

l. A method for killing microbes comprising the steps of contacting aninfected area with a composition comprised of a relatively nontoxic,normally relatively passive microbicidal compound which is stimulated tomicrobicidal activity by ultraviolet light, and stimulating saidcompound by exposure to light in the ultraviolet range of theelectromagnetic spectrum.

2. The method as claimed in claim 1 wherein the microbicidal compound isa member from the group consisting of acridine orange,azo-bis-iso-butyronitrile, benzil, benzoin, benzoyl peroxide, diacetyl,4,5-dibromo fluorescein Na, ethyl red, flazo orange, fluorescein amine,fluorescein isothiocyanate, lauroyl peroxide, methylene blue, and rosebengal.

3. The method as claimed in claim 1 wherein the microbicidal compoundincludes a biostrain.

4. The method as claimed in claim 1 wherein the microbicidal compound isa photopolymerization agent.

5. The method as claimed in claim 1 wherein the light in the ultravioletrange of the electromagnetic spectrum is surrounded by a curtain ofvisible light.

2. The method as claimed in claim 1 wherein the microbicidal compound isa member from the group consisting of acridine orange,azo-bis-iso-butyronitrile, benzil, benzoin, benzoyl peroxide, diacetyl,4,5-dibromo fluorescein Na, ethyl red, flazo orange, fluorescein amine,fluorescein isothiocyanate, lauroyl peroxide, methylene blue, and rosebengal.
 3. The method as claimed in claim 1 wherein the microbicidalcompound includes a biostrain.
 4. The method as claimed in claim 1wherein the microbicidal compound is a photopolymerization agent.
 5. Themethod as claimed in claim 1 wherein the light in the ultraviolet rangeof the electromagnetic spectrum is surrounded by a curtain of visiblelight.